Back Story of Ryoma Sengoku & Kudou Kugai
Ryoma Sengoku's (Kamen Rider Duke) had created a new Lock Seed which was being tested by Kudou Kugai. Kudou Kugai was the senior of Ryoma Sengoku. During the test of Ryoma's Lock Seed, this Lock Seed went out of control which along killed Kudou.
Back Story of Sid
Sid was originally an Hoodlum. He was beaten up by others hoods during this an Inves appears before them. Ryoma appears before Sid & save him.
Back Story of Yoko Minato
Minako was originally a Spy. Ryoma appeared before her & told her that he can fulfill her desire. Because of which she took interest in Ryoma & protected him as a Bodyguard.
Videos by Cast
Misora-chan acting Suspicious before Build: Be The One Press Conference